Embodiments of the invention relate to an inductor and a method for manufacturing the same.
As the wireless mobile communication field has rapidly been developed, high frequency resources have been in demand, and the request for a device and a circuit operating in the high frequency has been increased. The devices that are used in a high frequency region may be classified as radio frequency (RF) components and/or integrated circuits (IC's).
Also, as advanced processing techniques have been developed, complementary metal-oxide semiconductor (CMOS) circuitry has good high frequency characteristics. Since the CMOS manufacturing technology is based on silicon, it can manufacture a low-cost chip using well-developed processing techniques, and can integrate circuitry operating in an intermediate frequency band and digital circuitry and/or logic as part of a system such as a system on chip (SOC). Therefore, CMOS technology has been considered to be suitable process technology for manufacturing a single RF chip.
Meanwhile, the RF IC technique combines device manufacturing techniques, circuit design techniques, and high frequency packaging techniques. Only when the respective techniques are developed in balance, a competitive RF-CMOS device can be developed. To remain competitive, one important thing is to reduce the manufacturing costs. To this end, the process may be simplified and stabilized. The main constituents of RF-CMOS or bipolar/BiCMOS devices are a RF MOSFET, an inductor, a varactor, a metal-insulator-metal (MIM) capacitor, and a resistor.
In particular, although the inductor is indispensably used in a radio frequency chip, it occupies the largest area of the chip of any single device. Inductors also have many restrictions on the high frequency characteristics thereof, due to parasitic capacitance and resistance components that may depend on peripheral materials, structures, and internal materials.
The related art has generally applied planar spiral geometries for manufacturing an inductor. In other words, the top metal layer of a device or IC is implemented on a two-dimensional plane using certain geometric structures, represented by a rectangular type, an octagonal type, and a circular type, etc. Although the inductors in such various types can somewhat improve an inductance depending on the type, every type of inductor occupies a relatively large area in the high frequency chip.